Magnitude 9.0 earthquake off the west coast of Northern Sumatra (Sunday, December 26, 2004 at 00:58:49 UTC). Yellow circles indicate aftershocks. Image courtesy USGS.

12/28/2004 — Dr. Rob McCaffrey, a geophysics professor at Rensselaer Polytechnic Institute, has been monitoring earthquake activity and plate convergence at subduction zones in Indonesia, including the Sumatra subduction zone where the recent magnitude 9 earthquake occurred, and other regions for 25 years.

“Large earthquakes are common in South Asia, generating smaller tsunamis every few decades. But a magnitude 9 is very rare,” said McCaffrey. “This is about as big as it could get along that fault line. It will likely be many centuries before a magnitude 9 quake hits that section of the fault again, but a quake of similar size could occur along the fault south of Java.”

McCaffrey’s research interests include the analysis of geological, seismological, gravity, and geodetic data from convergent margins with attention to the structure, tectonics, and dynamics of subduction and collision. Regions studied include Indonesia, New Guinea, Taiwan, Panama, Central Asia, and the United States. McCaffrey uses teleseismic body waves and microearthquake networks to constrain the depths and mechanisms of earthquakes in order to understand collision processes. He also uses the Global Positioning System (GPS) to measure crustal formation and obtain a greater understanding of geologic processes.

“We examine earthquake statistics to understand what factors control when and where large earthquakes occur, measuring temperature of the faults, magnitude distributions, slip rates, etc.,” said McCaffrey. “The goal is to see how much we can learn about future earthquakes from what has happened in the past.”

McCaffrey joined Rensselaer in 1988. He received his PhD in geophysics from University of California at Santa Cruz and his bachelor’s in geophysics from Boston College.

More information: http://www.rpi.edu/~mccafr/sumatra04/

Media inquiries should be directed to Tiffany Lohwater, media relations specialist at Rensselaer, by phone at (518) 276-6542 or email at lohwat@rpi.edu.

Published December 28, 2004